Image processing takes place when using an image capturing device and a host machine, wherein images captured by the device are transferred to the host machine to undergo image processing for display.
In the interplay between an image capturing device and a host machine that processes the images from the device, a gradation of architecture choices are available for allocating the load of image processing between the device and the host machine.
In one conventional design approach, the major load of image processing occurs on the device. Captured images first undergo extensive processing performed by the device before being transferred to the host machine for further processing. In another conventional design approach, the major load of image processing occurs on the host machine. Other design approaches fall somewhere in between the above two extreme approaches.
The sheer number of these possible design approaches leads to the cumbersome process of creating an image capturing device driver design per image capturing device design. Moreover, even when an image capturing device driver is created for a specific design approach, certain image processing can still expose the weakness of the driver. For example, in applications such as capturing and displaying real time streaming video, the conventional device drivers do not take into account the effect of variations associated with the interaction between the device and the host machine.
Variations can relate to static aspects and dynamic aspects of an image processing system that includes the device and the host machine. Specifically, variations in static aspects in the image processing system refer to variations of characteristics for the device and the host machine. For example, transceiver type can vary from device to device and from host machine to host machine. Also, hardware architecture can vary from host machine to host machine. On the other hand, variations in dynamic aspects of the image processing system refer to variations of real time characteristics of the device and the host machine. For example, the USB coupling bandwidth can be changing in real time, depending on whether another USB device is coupled to the host machine. The CPU of the host machine can be also executing instructions from another application. The memory and buffering capacity can vary in real time. The frame rate can vary depending on the real time requirement of the running application.
However, the quality of the displayed images suffers because a conventional driver is not able to adjust to these possible variations. Even if an image capturing device driver on the host machine can be tailored to the static characteristics of the image capturing device and the host machine, doing so for each design approach is cumbersome and impractical. Moreover, the conventional driver cannot respond properly to the dynamic variations.